#define LED_PIN 12
void setup() {
  // put your setup code here, to run once:
pinMode(LED_PIN,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
for (int i =0;i<256;i++){
analogWrite(LED_PIN,i);
delay(10);
}
for (int i =255;i>=0;i--){
analogWrite(LED_PIN,i);
delay(10);
}
}
